Hemorrhoids are swollen
veins in the
anal canal. This common problem can be painful, but
it's usually not serious.

Veins can swell inside the anal canal to
form internal hemorrhoids. Or they can swell near the opening of the anus to
form external hemorrhoids. You can have both types at the same time. The
symptoms and treatment depend on which type you have.

Too much pressure on the
veins in the pelvic and rectal area causes hemorrhoids.

Normally,
tissue inside the anus fills with blood to help control bowel movements. If you
strain or sit on the toilet a long time to move stool, the increased pressure causes the veins in this tissue to
swell and stretch. This can cause hemorrhoids.

Diarrhea or
constipation also may lead to straining and can increase pressure on veins in
the anal canal.

Pregnant women can get hemorrhoids during the
last 6 months of pregnancy. This is because of increased pressure on the blood
vessels in the pelvic area. Straining to push the baby out during labor can
make hemorrhoids worse.

Being overweight can also lead to
hemorrhoids.

The most common symptoms of
both internal and external hemorrhoids include:

Bleeding during bowel movements. You might
see streaks of bright red blood on toilet paper after you strain to have a
bowel movement.

Itching.

Rectal pain. It may be
painful to clean the anal area.

With internal hemorrhoids, you may see bright red streaks of blood on toilet
paper or bright red blood in the toilet bowl after you have a normal bowel
movement. You may see blood on the surface of the stool.

Internal
hemorrhoids often are small, swollen veins in the wall of the anal canal. But
they can be large, sagging veins that bulge out of the anus all the time. They
can be painful if they bulge out and are squeezed by the anal muscles. They may
be very painful if the blood supply to the hemorrhoid is cut off. If
hemorrhoids bulge out, you also may see mucus on the toilet paper or
stool.